AES 2011 Day 3

Time for the recap of day 3 of JMIH/AES 2011.  Read on below the jump…

Due to the fact that my roommates didn’t set the alarm this morning (right, that’s what I’ll blame it on), I missed talks by Dovi Kacev and Austin Gallagher.  Sorry guys, can’t make ’em all…

The Gruber award student presentations wrapped up during the morning session.  The first one I made it to was Andrea Kroetz’s study on the ecology of bonnethead sharks in the coastal waters of Alabama.  She found that bonnies mainly stick to the west side of Dauphin Island and don’t move around much, and this correlates with where most of the area’s blue crabs (a favorite food of bonnetheads) are found.  A rock wall built across an inlet opened by Hurricane Katrina may disrupt the movements of these sharks and some of the other species there.  Gavin Naylor filled in for his student Corey Eddy to show that Galapagos and dusky sharks may actually be the same species, or there might actually be several species between them depending on which side of the Atlantic or Pacific they’re on.  Gotta love genetics for taxonomy.  Andy Nosal presented his research on the leopard shark aggregation at La Jolla, California.  It turns out that, despite being relatively unsheltered, the aggregation site is near a steady food source (found via gastric lavage!), may provide some defense from predators, and the sharks may be attracted by some anomaly involving the fault line going straight through the area with the densest concentrations of sharks.  Bryan Legare finished off the Gruber talks by recounting his acoustic telemetry research on newborn blacktip and lemons sharks in the U.S. Virgin Islands.  The bays of St. Thomas appear to be pretty important nursery areas for both species, and he was able to figure out the timing of the pups’ arrival and departure from the bays.

During the lunch hour Aleksandra Malijkovic hosted a graduate student workshop/panel discussion on the role of research in shark conservation that featured Sonja Fordham, Neil Hammerschlag, Tonya Wiley, and Nick Dulvy.  The take-home message was to be as practical and specific as you can when giving scientific advice for conservation measures.  It’s a lot easier to ignore something vague like “sharks can’t handle fishing pressure” than a statement like “the quote should be 15,000 tons.”  Also, social media and the internet are giving scientists much easier and effective ways of communicating their work than traditional publishing methods.

After the panel discussion I headed over to watch Greg Skomal present data on the correlation between increased gray seal numbers on Cape Cod and an increase in white shark sightings.  Aside from the fact that I’m somewhat obsessed with New England great whites, this talk is also timely.  Comparing the Cape Cod situation to previous research from the West Coast on white sharks returning to an area, it looks like New England is still in the early stages of being recolonized by great whites.  Perhaps southern New England could become a new global white shark hot spot?

There has been a solid one spiny dogfish talk per day, which makes it easy for me to keep track of them.  Mauro Bellaggia introduced us to the spiny dogfish of Argentinian waters, where their trophic level appears to be affected by fishing pressure on the Argentinian hake, their former most important prey.  While fish overall and hake in particular have declined in the diet of dogfish, gelatinous organisms like ctenophores and jellyfish have increased, as have squid.  Because trophic level is affected by the trophic level of the prey animals, spiny dogfish off of Argentina have seen theirs lowered from 4.5 to just over 4.0.

I finished off the day by watching a couple talks about the anatomy and mechanics of sharks.  Lyndell Bade discussed assymetry in the female reproductive tract based on habitat and migration behavior, and may have found some connections between the number of uteri/ovaries used and which side is more dominant and the depth the sharks are found at.  Ashley Stoehr talked about the jaw movements of spiny dogfish, bamboo sharks, and little skates, and it looks like spiny dogfish have the most versatile jaw movement of any of the species.  This is in keeping with their generalist feeding methods, previously discussed in this post, and is yet another reason why dogfish are the noblest of sharks.

As always, feel free to bring up anything I missed or didn’t mention in the comments.  More shark talks tomorrow.  Booyah!

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